Sony KDL-40ex400 LCD tv no power...100% dead

[shelby5041]

Re: Sony KDL-40ex400 LCD tv no power...100% dead

ok ill check pin 2 voltages rught now

[shelby5041]

Re: Sony KDL-40ex400 LCD tv no power...100% dead

ok pin 2 on ic6301

v is .04v when ps plugged in

v is .04v when pwr on is applied via jumping standby to pwr on pin

[budm]

Re: Sony KDL-40ex400 LCD tv no power...100% dead

Did you see the dot on the spec sheet, so I am not sure what you mean by "so is pin 2 to the right if 1." To the right???
You also must use correct ground ref point for the meter since now you are checking the voltage in the primary (deadly side) side of the circuit, you cannot use the chassis for your meter, and do not touch anything in that section! The ground ref point will be the negative leg of the main filter cap C6325. Again, do not touch anything in that section with your hands or body, and do not let the probes slip on you.

[budm]

Re: Sony KDL-40ex400 LCD tv no power...100% dead

ok pin 2 on ic6301

v is .04v when ps plugged in

v is .04v when pwr on is applied via jumping standby to pwr on pin

What did you use for the ground for your meter?

[shelby5041]

Re: Sony KDL-40ex400 LCD tv no power...100% dead

the board is not in tv....im doing this on table...im at work brought board in....ill c if i can do what u said for grounding...nervous now since high voltage side....

[shelby5041]

Re: Sony KDL-40ex400 LCD tv no power...100% dead

just touched one of the pins labeled ground

[shelby5041]

Re: Sony KDL-40ex400 LCD tv no power...100% dead

that cap is 450v.....im not sure i should try...im not trained

[shelby5041]

Re: Sony KDL-40ex400 LCD tv no power...100% dead

off the subject but i have a pack of new n mosfets i was comparing yesterday while learning.....today my meter is giving me a value of 700 diode setting source to drain and it wont go away...if i touch source to gate with fibgers it doesnt go to nothing.....all of the n mosfets i have are testing that way today.....yesterday source to drain was open.......????????? until i energized gate.....i dont know why they all seem bad now....they r all new

[shelby5041]

Re: Sony KDL-40ex400 LCD tv no power...100% dead

have to go ..at work.....thanks

[shelby5041]

Re: Sony KDL-40ex400 LCD tv no power...100% dead

thanks budm

i am going to try to test pin 2 using the large cap neg as ground

to be safe i will electrical tape off all areas around pin 2 so i dont touch anything else and also other areas of board to be safe

ill let u know later what i get

ill check pin 2 voltage without pwr on applied and then with pwr on applied correct?

[shelby5041]

Re: Sony KDL-40ex400 LCD tv no power...100% dead

like i said shop jimmy sells a 12 pc set of componenets for this power supply on ebay for 27.00............but the issue is i will not continue trying to repair this tv if main board and power supply bad since it wont be worth it .....new tvs are so cheap ...repairing tvs now really isnt as good of an idea as it used to be..........if i can repair it cheap i repair it..if not i toss the tv out ...thats unfortunate but thats just how the electronics industry is nowadays....most everything is considered dispoisable.....wish the good ol days were back ........when fixing things was a good thing

[shelby5041]

Re: Sony KDL-40ex400 LCD tv no power...100% dead

remember when plasma tvs were 3k to 10k and lcd tvs were over 1k???

now plasma tvs are 399.99 for a 50 inch 1080p

nd lcd tvs under 200.00 for 42 inch 1080p


laptops are same way....i sued to like repairing laptop computers but not anymore since a new laptop is only 199.00..............repairing just doesnt make sense

its more of a hobby that i like to tinker with here and there....i have no education with electronics just gather info from people like u and has helped me do a lot of basic troubleshotting....its fun

[budm]

Re: Sony KDL-40ex400 LCD tv no power...100% dead

I do not do repair works for living, it is good for learning experience which is worth a lot to me to use and apply to my line of work on what not to do when design the products. You cannot beat hands on experience.

[tom66]

Re: Sony KDL-40ex400 LCD tv no power...100% dead

It's becoming less worth it now for me too. In another year or so, it's not going to be worth fixing anything that isn't a superthin LED TV. And so many of them have bad panels...

[shelby5041]

Re: Sony KDL-40ex400 LCD tv no power...100% dead

tom m thats a very accurate statement...........not even sure why tv repair shops are even around.....they cant be doing very well

remember when crt tvs were expensive and was worth spening 100.00 to get it repaired

in the old days a 32 inch sony crt would run about 600.00


and back in the early 70s and 80s tvs were even more........electronics industry as a whole has become disposable and thats a fact

the problem is china..and india..........and out government allowing them to send products here for free............usa cant compete with hourly wages in china and india at about 10 cents an hour.....oh well


back to my issue lol

ill try testing voltages shortly im at work right now and when i get a min i will do some testing

[shelby5041]

Re: Sony KDL-40ex400 LCD tv no power...100% dead

fyi even worse is you got these ebayers and other tv parts sellers trying to sell older model lcd and plasma tv parts for more than buying a new tv..........why????

parts for lcd tvs older then 5 yrs should be real cheap but they arent....they are trying to rip people off ...but it actually hurts them in long run....example...why would someone pay 100.00 for a power supply for a old polaroid lcd tv when they can buy a brand new lcd tv for same price..with better features....and new.....i always wonder the strategy they use....its not a good idea......supply and demand doesnt apply here since a new lower cost lcd tv is now an option instead of repairing the old tv....

[shelby5041]

Re: Sony KDL-40ex400 LCD tv no power...100% dead

hi budm

i want to try to test pin 2 today....i want to make sure i have it right

u want me touch neg side of large 450v cap with neg probe and pos probe to pin 2?

[Agent24]

Re: Sony KDL-40ex400 LCD tv no power...100% dead

Yes, that would make sense - you are measuring on the primary side of the PSU so the ground reference has to be hot ground - which is the negative lead of the main capacitor (and anything it's connected to)

When measuring voltage on the secondary side, you use the chassis, or cold ground.

Getting them mixed up will mean you'd get incorrect voltage measurements.

[shelby5041]

Re: Sony KDL-40ex400 LCD tv no power...100% dead

hi update i bought a new mainboard and still 100% dead...no standby light even though i do have 3.3 standby voltage..........

[budm]

Re: Sony KDL-40ex400 LCD tv no power...100% dead

Post #70

thanks budm

i am going to try to test pin 2 using the large cap neg as ground

to be safe i will electrical tape off all areas around pin 2 so i dont touch anything else and also other areas of board to be safe

ill let u know later what i get

ill check pin 2 voltage without pwr on applied and then with pwr on applied correct?

Poat #77

hi budm

i want to try to test pin 2 today....i want to make sure i have it right

u want me touch neg side of large 450v cap with neg probe and pos probe to pin 2?

Post 79

hi update i bought a new mainboard and still 100% dead...no standby light even though i do have 3.3 standby voltage..........

So we never finish testing the power supply and now you bought the new MAIN board, and I am not about to go back and read the old posts form August again.